Packaging membrane with built-in opening feature

ABSTRACT

A packaging membrane comprising a laminate of at least first and second layers, having a removable portion formed by substantially coincident first and second score lines, the first score line being formed in the first layer but not breaching the second layer, and the second score line being formed in the second layer but not breaching the first layer. Optionally, a third layer is disposed between the first and second layers, and the third layer is not breached by either score line. In the removable portion, an adhesive-free region is provided within which the first layer is not adhered to the underlying layer(s). An integral tab is defined in the first layer within the adhesive-free region, the tab being formed by a cut line in the first layer. The tab is located entirely inside the first and second score lines and does not project beyond any edge of the membrane.

BACKGROUND OF THE INVENTION

The present disclosure relates generally to containers for products, andmore particularly to containers formed at least in part by a flexiblemembrane material, and wherein the membrane defines an opening featurefor creating an opening through the membrane to gain access to thecontents of the container.

Various types of such containers have been developed or proposed overthe years, having a variety of opening features. Some such containersemploy additional separately formed components such as labels or tabsaffixed to the membrane to allow the consumer to grasp and pull the tabin order to sever the membrane along a preformed line of weakness. Theuse of such separate components complicates the process of manufacturingthe containers, as the components have to be procured, inventoried, fedinto the manufacturing process, properly registered with the membranesto which they are attached, etc.

It is also known to provide a membrane with an integral tab thatprojects beyond an edge of the membrane, or beyond an edge of aremovable portion of the membrane, to facilitate grasping and pullingthe membrane or removable portion thereof. Such projecting tabs cancause problems in automated handling of packages because they can getstuck on equipment and cause jams in the manufacturing line. In othercases, such a projecting integral tab is folded back onto the membraneso as not to project beyond the edge of the membrane, but to keep thetab from unfolding it is frequently necessary to tack the tab down witha spot of adhesive or by other means. The tab folding and tackingoperations further complicate the manufacturing process.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure relates to a membrane for a container, in whichthe membrane has an integral opening feature in the form of a removableportion that is at least partially removable from the remainder of themembrane. The membrane comprises a laminate of at least first and secondlayers adhesively laminated together. The removable portion is formed bysubstantially coincident first and second score lines, the first scoreline being formed in the first layer but not breaching the second layer,and the second score line being formed in the second layer but notbreaching the first layer. In one embodiment there is a third layerdisposed between the first and second layers, and the third layer is notbreached by either score line. The third layer can comprise an easilyseverable material such as aluminum foil or the like, which also servesas a barrier to the passage of moisture and gases through the membrane.The first and second layers can comprise polymer film materials and/orpaper, or the like.

In the removable portion of the membrane, an adhesive-free region isprovided within which the first layer is not adhered to the underlyinglayer(s). The adhesive-free region occupies less than the entire area ofthe removable portion. An integral tab is defined in the first layerwithin the adhesive-free region, the tab being formed by a cut line inthe first layer. The tab is located entirely inside the bounds of thefirst and second score lines, and thus the tab does not project beyondany edge of the membrane. The tab can be lifted and pulled in order tosever the membrane along the score lines so as to at least partiallyremove the removable portion of the membrane and thereby gain access tothe interior of the container through the resulting opening formed inthe membrane. A coating of a release material can be disposed between alower surface of the tab and an upper surface of the underlying layer toprevent the tab from sticking thereto, although in many cases no releasematerial may be required.

In one embodiment, the score lines form a closed loop such that theremovable portion is completely removable from the rest of the membrane.

In some embodiments, the membrane comprises a lid that is attached to aseparately formed container to close an opening in the container.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the disclosure in general terms, reference willnow be made to the accompanying drawings, which are not necessarilydrawn to scale, and wherein:

FIG. 1 is a perspective view of a container having a membrane lid inaccordance with one embodiment of the invention;

FIG. 2 is a cross-sectional view through the membrane lid along line 2-2in FIG. 1, with the layers of the membrane shown disproportionatelythick for improved clarity of illustration;

FIG. 3 is a view similar to FIG. 2, showing another embodiment; and

FIG. 4 is a diagrammatic depiction of a process for making a membrane inaccordance with one embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention now will be described more fully hereinafter withreference to the accompanying drawings in which some but not allembodiments of the inventions are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

A first embodiment of the invention is illustrated in FIGS. 1 and 2.FIG. 1 shows a container 10 comprising a container body 12 and a lid inthe form of a membrane 20 affixed to a surface of the container bodycovering an opening therein. The container body 12 can comprise any ofvarious materials, constructions, and shapes. For example, the containerbody can be made of plastic, paper, metal, or combinations of two ormore such materials. In the case of plastic, the container body can bemade by molding (e.g., injection molding, blow molding, etc.),thermoforming, or the like. In the case of paper or composites of paperwith plastic and/or metal foil, the container body can be made bywinding or wrapping layers of the materials about a suitable formingmandrel and adhering the layers together to form a tubular containerbody, a lower end of which can be closed with a separate closure (notshown). In the case of metal, the container body can be formed bydrawing or die forming. The particular details of the container body andits manufacture are not of particular importance to the invention.

The membrane 20 comprises a flexible laminate of at least two layersthat are adhesively joined together. The layers are coextensive witheach other, i.e., they have the same surface area and their respectiveedges are aligned such no edge of any layer extends beyond acorresponding edge of the other layer(s). The layers can comprisevarious materials such as polymer film, metal foil, paper, orcombinations thereof. Suitable examples of polymer films that can beemployed include but are not limited to polyethylene, polypropylene,polyamide, polyester, and the like. The film can be oriented if desired.Metallized film (i.e., film having a vapor-deposited layer ofnon-oxidized metal such as aluminum) can be employed. Film coated with aceramic layer such as silicon oxide or aluminum oxide can be used.

The membrane 20 includes a removable portion 22 that can be at leastpartially removed from the remainder of the membrane in order to form anopening through the membrane into the interior of the container. Theremovable portion 22 is provided by scoring the layers of the membraneto create a line of weakness along which the membrane can be severed.

More particularly, with reference to FIG. 2, in this embodiment themembrane 20 comprises a laminate of a first layer 24 and a second layer26 laminated to the first layer by an adhesive layer 28. The removableportion 22 of the membrane is formed by scoring the first layer along afirst score line L₁. The first score line extends partially or entirelythrough the thickness of the first layer 24, but does not breach thesecond layer 26. The second layer is scored along a second score line L₂that extends partially or entirely through the thickness of the secondlayer 26 but does not breach the first layer 24. The score lines can beformed by mechanical means such as kiss cutting or by using a laser toscore the layers. The first and second score lines L₁ and L₂ aresubstantially coincident in location with respect to directions in theplane of the laminate—that is, the first score line substantiallydirectly overlies the second score line. When there is no interveningfilm or foil layer between the first and second layers as in theembodiment of FIG. 2, if desired the score lines can be slightly offsetrelative to each other in order to reduce the likelihood of prematureinadvertent separation of the laminate along the score lines.

In order to facilitate grasping the removable portion 22 to sever itfrom the rest of the membrane, the membrane includes an integral tab 30formed in the first layer 24. The tab is formed by a cut line 32 thatextends entirely through the thickness of the first layer. The cut line32 can have various shapes, a generally U-shaped cut line being shown inFIG. 1, so as to define a tab that has a free end at the closed end ofthe “U” and a fixed end at the open end of the “U”.

In order to allow the tab 30 to be lifted from the layer underlying it,the membrane 20 includes an adhesive-free region 40 that is within thebounds of the score lines L_(1,2). The adhesive layer 28 is absent inthe adhesive-free region, and thus the layers 24, 26 are not affixed toeach other in this region. In the embodiment illustrated in FIGS. 1 and2, the adhesive-free region 40 is spaced on all sides from the scorelines defining the removable portion 22 of the membrane. Accordingly,between the edges of the adhesive-free region 40 and the edges of theremovable portion 22 there is a marginal region 42 in which the layers24, 26 are adhesively joined to each other, and this marginal regioncompletely surrounds the adhesive-free region. The ends of the cut line32 for the tab can lie in the adhesive-free region 40 as shown in FIG.1, or alternatively can lie in the marginal region 42 where there isadhesive.

If desired or needed, a coating of a release material can be applied tothe underside of the tab 30 or to the surface of the layer directlyunderlying the tab to prevent the tab from sticking to the underlyingsurface.

The membrane 20 in the embodiment of FIG. 1 is rectangular in shape,although other shapes can be used. The rectangular membrane 20 includesa first edge E₁, a second edge E₂ that is perpendicular to the firstedge, a third edge E₃ that is perpendicular to the second edge andparallel to the first edge, and a fourth edge E₄ that is perpendicularto the first and third edges and parallel to the second edge. In theillustrated embodiment, the removable portion 22 of the membrane ispositioned closer to the first edge E₁ than to the third edge E₃,although other positions can be used. The pulling direction along whichthe tab 30 is pulled extends from the fourth edge E₄ toward the secondedge E₂, and thus is generally parallel to the first and third edges andperpendicular to the second and fourth edges.

To open the container shown in FIG. 1, the user lifts the tab 30 andgrasps it, and pulls the tab generally upwardly and in the pullingdirection from the fourth edge E₄ toward the second edge E₂, whichcauses the membrane to sever beginning at the edge of the removableportion 22 adjacent the fixed end of the tab and proceeding around thescore lines L_(1,2) toward the second edge E₂. In the illustratedembodiment, the score lines form a closed loop such that the removableportion 22 comes entirely free of the rest of the membrane.Alternatively, the score lines could be configured to leave a portion ofthe removable portion still attached to the membrane, thus forming aflap. In any event, an opening is thereby created through the membraneinto the container.

A second embodiment of the invention is depicted in FIG. 3. The membrane120 of this embodiment is a three-layer laminate, whereas the membrane20 of the previous embodiment is a two-layer laminate (the adhesivelayer(s) not being counted in both cases). The membrane 120 includes afirst layer 124, a second layer 126, and a third layer 129. The thirdlayer is disposed between the first and second layers. The first andsecond layers 124, 126 each comprise a polymer film. The third layer 129comprises a metal foil such as aluminum foil. An adhesive layer 125 isdisposed between the first layer 124 and the third layer 129 for joiningthese layers together, and an adhesive layer 127 is disposed between thesecond layer 126 and the third layer 129 for joining these layerstogether.

In one embodiment, the first layer 124 can comprise a polyester filmsuch as polyethylene terephthalate. The second layer 126 can comprise anoriented polypropylene (OPP) film. The OPP film is heat-sealable to acompatible heat seal material disposed on the container. Otherheat-sealable films can also be used instead of OPP.

The first layer 124 and second layer 126 include respective first andsecond score lines L₁ and L₂ as in the previous embodiment for defininga removable portion 122 of the membrane. The first score line extendsthrough the first layer 124 but does not breach the third layer 129. Thesecond score line likewise extends through the second layer 126 but doesnot breach the third layer 129. A tab 130 is defined in the first layer124 by a cut line 132. An adhesive-free region 140 is defined within theremovable portion 122, in which the first layer 124 is not adhered tothe third layer 129, and the tab 130 is located in the adhesive-freeregion.

The membrane 120 operates in a manner similar to the membrane 20previously described. Pulling on the tab 130 causes the membrane tosever along the score lines. Although the foil layer 129 is not scored,the foil will easily sever when the plastic layers 124, 126 begin tosever. However, prior to being severed, the foil layer provides a goodbarrier against moisture and gases.

The membranes 20, 120 can be manufactured using a continuous web processin which continuous webs of the various layers are advanced through aseries of stations at which various operations are performed on the websand the webs are laminated together. For example, a manufacturingprocess for making the laminate 120 is depicted in FIG. 4. A continuousweb of the second layer 126 is advanced from a supply roll thereof to anadhesive applicator 150 that applies a coating of the adhesive 127 tothe second layer. The web is then conveyed to a lamination station 160where the second layer 126 is laminated to the third foil layer 129,which is advanced to the lamination station from its own supply roll,thus resulting in a laminate 170 of these two layers.

Either concurrently or non-concurrently with the formation of thelaminate 170, a continuous web of the first layer 124 is advanced from asupply roll thereof to a tab-forming station at which a cuttingmechanism 180 forms the cut lines defining the tabs in the first layer.The tab cut lines are formed in the laminate at fixed distance intervalsalong the length of the web such that a series of interconnectedmembrane lids can be formed from the continuous web. In the illustratedembodiment, the cutting mechanism 180 comprises a laser, but othercutting mechanisms can be used instead. Next, the first layer isadvanced to an adhesive applicator 190 that pattern-applies the adhesive125 onto the first layer such that adhesive-free regions are left. Theadhesive-free regions are in registration with the tab cut lines suchthat the tabs are located in the adhesive-free regions. The adhesiveapplicator 190 can comprise any suitable device capable ofpattern-applying the adhesive, such as a gravure roll or the like. Thefirst layer with the adhesive thereon is then advanced to a laminationstation 200 where the first layer is laminated with the laminate 170comprising the second and third layers 126, 129.

Finally, the resulting laminate is advanced to a second scoring station210 at which the second score lines are formed in the second layer 126in registration with the tab cut lines and adhesive-free areas, and afirst scoring station 220 at which the first score lines are formed inthe first layer 124 in registration with the second score lines. Thescoring stations 210, 220 are illustrated as comprising lasers, butother scoring mechanisms can be used instead. The scoring stations 210,220 are shown as being separated by a distance in the web traveldirection, but alternatively they can be located at the same place alongthe travel direction.

The order of operations shown in FIG. 4 can be altered. For example, thetab-forming station 180 can be located downstream of the laminationstation 200, and one or both of the scoring stations 210, 220 can belocated upstream of the tab-forming station. It is also possible for thetab-forming station 180 and the first scoring station 220 to be the samestation such that the tab cut line and the first score line are formedin the first layer 124 substantially simultaneously. Other changes alsocan be made to the process.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. A membrane for forming at least a portion of a container forproducts, comprising: a laminate comprising at least first and secondlayers laminated together by an adhesive, the first and second layersbeing coextensive; a first score line formed in the first layer, thesecond layer being unbreached by the first score line; a second scoreline formed in the second layer and located substantially coincidentwith the first score line, the first layer being unbreached by thesecond score line, the first and second score lines together delineatinga removable portion of the laminate that is at least partially removablefrom a remainder of the laminate for creating an opening through themembrane; an adhesive-free region located in the removable portion ofthe laminate and occupying less than an entire area thereof, the firstand second layers being unadhered to each other in the adhesive-freeregion; and an integral tab formed in the first layer within theadhesive-free region, the tab being formed by a cut line extendingthrough a thickness of the first layer, the tab being located entirelyinside of the first and second score lines.
 2. The membrane of claim 1,wherein the first and second score lines form a closed loop such thatthe removable portion is completely removable from the remainder of thelaminate.
 3. The membrane of claim 2, wherein the membrane isrectangular having a first edge, a second edge perpendicular to thefirst edge, a third edge perpendicular to the second edge and parallelto the first edge, and a fourth edge perpendicular to the first andthird edges and parallel to the second edge, and wherein the removableportion of the laminate is spaced relatively close to the first edge andrelatively far from the third edge.
 4. The membrane of claim 3, whereinthe second and fourth edges are longer than the first and third edges.5. The membrane of claim 4, wherein the tab is oriented such that apulling direction, in which the tab is pulled to detach the removableportion from the remainder of the membrane, extends generallyperpendicular to the second and fourth edges.
 6. The membrane of claim1, wherein a coating of a release material is disposed between a lowersurface of the tab and an upper surface of the second layer underlyingthe tab to prevent the tab from sticking to the second layer.
 7. Amembrane for forming at least a portion of a container for products,comprising: a laminate comprising first, second, and third layerslaminated together by adhesive, the layers being coextensive, the thirdlayer disposed between the first and second layers; a first score lineformed in the first layer, the second and third layers being unbreachedby the first score line; a second score line formed in the second layerand located substantially coincident with the first score line, thefirst and third layers being unbreached by the second score line, thefirst and second score lines together delineating a removable portion ofthe laminate that is at least partially removable from a remainder ofthe laminate for creating an opening through the membrane; anadhesive-free region located in the removable portion of the laminateand occupying less than an entire area of the removable portion, thefirst and third layers being unadhered to each other in theadhesive-free region; and an integral tab formed in the first layerwithin the adhesive-free region.
 8. The membrane of claim 8, wherein thefirst and second layers comprise polymer layers and the third layercomprises a metal foil layer.
 9. The membrane of claim 8, wherein thefirst and second score lines form a closed loop such that the removableportion is completely removable from the remainder of the laminate. 10.The membrane of claim 8, wherein the membrane is rectangular having afirst edge, a second edge perpendicular to the first edge, a third edgeperpendicular to the second edge and parallel to the first edge, and afourth edge perpendicular to the first and third edges and parallel tothe second edge, and wherein the removable portion of the laminate isspaced relatively close to the first edge and relatively far from thethird edge.
 11. The membrane of claim 10, wherein the second and fourthedges are longer than the first and third edges.
 12. The membrane ofclaim 11, wherein the tab is oriented such that a pulling direction, inwhich the tab is pulled to detach the removable portion from theremainder of the membrane, extends generally perpendicular to the secondand fourth edges.
 13. The membrane of claim 8, wherein a coating of arelease material is disposed between a lower surface of the tab and anupper surface of the second layer underlying the tab to prevent the tabfrom sticking to the second layer.
 14. The membrane of claim 8, whereinthe tab is located entirely inside of the first and second score lines.15. The membrane of claim 1, wherein the membrane comprises a lid, andfurther comprising a separately formed container defining an opening,the lid being affixed to the container to cover the opening.
 16. Themembrane of claim 8, wherein the membrane comprises a lid, and furthercomprising a separately formed container defining an opening, the lidbeing affixed to the container to cover the opening.